This allows the allocator to free any resources used by the virtual register,
including physical register assignments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127560
91177308-0d34-0410-b5e6-
96231b3b80d8
MI->eraseFromParent();
}
- // FIXME: Notify the register allocator that the snippets are now dead.
+ for (unsigned i = 0, e = RegsToSpill.size(); i != e; ++i)
+ edit.eraseVirtReg(RegsToSpill[i], lis_);
}
return lis.InsertMachineInstrInMaps(--MI).getDefIndex();
}
+void LiveRangeEdit::eraseVirtReg(unsigned Reg, LiveIntervals &LIS) {
+ if (delegate_ && delegate_->LRE_CanEraseVirtReg(Reg))
+ LIS.removeInterval(Reg);
+}
+
void LiveRangeEdit::eliminateDeadDefs(SmallVectorImpl<MachineInstr*> &Dead,
LiveIntervals &LIS,
const TargetInstrInfo &TII) {
struct Delegate {
/// Called immediately before erasing a dead machine instruction.
virtual void LRE_WillEraseInstruction(MachineInstr *MI) {}
+
+ /// Called when a virtual register is no longer used. Return false to defer
+ /// its deletion from LiveIntervals.
+ virtual bool LRE_CanEraseVirtReg(unsigned) { return true; }
+
virtual ~Delegate() {}
};
return rematted_.count(ParentVNI);
}
+ /// eraseVirtReg - Notify the delegate that Reg is no longer in use, and try
+ /// to erase it from LIS.
+ void eraseVirtReg(unsigned Reg, LiveIntervals &LIS);
+
/// eliminateDeadDefs - Try to delete machine instructions that are now dead
/// (allDefsAreDead returns true). This may cause live intervals to be trimmed
/// and further dead efs to be eliminated.
private:
void LRE_WillEraseInstruction(MachineInstr*);
+ bool LRE_CanEraseVirtReg(unsigned);
bool checkUncachedInterference(LiveInterval&, unsigned);
LiveInterval *getSingleInterference(LiveInterval&, unsigned);
VRM->RemoveMachineInstrFromMaps(MI);
}
+bool RAGreedy::LRE_CanEraseVirtReg(unsigned VirtReg) {
+ if (unsigned PhysReg = VRM->getPhys(VirtReg)) {
+ unassign(LIS->getInterval(VirtReg), PhysReg);
+ return true;
+ }
+ // Unassigned virtreg is probably in the priority queue.
+ // RegAllocBase will erase it after dequeueing.
+ return false;
+}
void RAGreedy::releaseMemory() {
SpillerInstance.reset(0);